Saturday, 23 May 2015

God, evolution, global warming and heart disease: a personal reflection on population health

An ‘inaugural’ lecture given in the Nuffield Department of Population
Health at the University of Oxford, on 18th May 2015, for my Professorship in Population Health. For the slides see: here .

In general I think you should never apologise when giving
lectures but I am going to start this lecture with three apologies.

Firstly I know that it is conventional to give lots of
acknowledgements in an inaugural lecture but I only have two: firstly to the
University of Oxford, and in particular Professor Rory Collins, for awarding me
this professorship and secondly to the British Heart Foundation for paying my
salary for the last 22 years. There are
too many other people I should thank so to avoid missing people out I will stop
there. Sorry. I will however in the course of this lecture
acknowledge some of the people who have affected my thinking about population
health.

Secondly I also know that it is conventional to try to be
inspirational in an inaugural lecture.
I would like to be inspirational but my trajectory from DPhil student in
the Department of Zoology to Professor of Population Health has hardly been
‘conventional’ and I would not advise anyone else to follow my example. So I am sorry if you’d come to this lecture
hoping to hear some tips on how to become a Professor of Population Health. I do however hope to inspire you to think
differently about population health.

Thirdly this lecture is more valedictory than
inaugural. This seems to inevitable
given that I have been working in the field of population health for about 30
years and by my reckoning I have less than ten years left. I have
fought against the consequent temptation to be self-referential and even worse
self-indulgent but you’ll see that I haven’t been able to resist these
temptations completely. Sorry.

I have chosen as the title for this lecture God, evolution,
global warming and heart disease, not because I am an expert on these four
things but because all four topics have figured extensively in my intellectual
life: much as particular songs or pieces of music provide the sound track of one’s
general life. Incidentally the actual
piece of music which has done this most for me is ‘Without You’ by Nilsson. Don’t’
worry I won’t be playing you a clip: that would just be too
self-indulgent. I guess we all have many pieces of music that
provide the sound track to our lives and there are more topics I could have included
in this list: foods and diets being an obvious one.

These four topics of God, evolution, global warming and
heart disease do I think have a relationship with population health and the aim
of lecture is merely to persuade you that they do. It is clearly obvious that heart disease is
relevant to population health but, of course, less so when it comes to God,
evolution and global warming.

[OHP] Here then are four paintings of God, evolution, global
warming and heart disease. Three of
these paintings were painted by my friends for me. Top left is a painting of Jesus’ miracle of
turning water into wide at a wedding at Cana which hangs in my office. It depicts God in the shape of an actual living
person – I don’t know his name - who represents Jesus, second from the
left. God has always been an important
topic in my life. So much so that I
became an Anglican priest in 2008 as many of you know. Theologians have much to say about health.

Top right is a painting by Desmond Morris that illustrates
the front cover of the first edition of a book called ‘The Selfish Gene’ by
Richard Dawkins. The Selfish Gene was
published in 1976 while I was studying for a degree in Zoology here at Oxford and
I had some tutorials with Richard Dawkins.
I think the book has been very important in the way we think about many things
including health: perhaps even comparable in its influence to Charles Darwin’s ‘On
the Origin of the Species’ published in 1860. I do not think the influence of either book has
been good.

Bottom right is a painting entitled ‘Global Warming’. Since around the mid 1990’s - through meeting
an energy scientist called Alwyn McKay who had worked with Nils Bohr in Copenhagen.
I have increasingly come to see that that
global warming is a much bigger problem for the human species than anything
else including heart disease. And this
has had an influence on my perspective on population health as I’ll briefly explain
later

Finally the last painting, bottom left, is entitled ‘Heart Disease’ Heart
disease is a topic that I have been concerned with since 1986 when I joined the
staff of a non-governmental organisation called the Coronary Prevention Group. I guess this picture’s does not make for comfortable
viewing but it reminds us that heart disease isn’t in the end a comfortable
subject – it affects people we know and love including some of us here. It is an evil that many in this department of
population health are seeking to eradicate or at least to ameliorate.

This picture obviously has both theological and biological
references: the three hooded figures represent – at least to my way of thinking
- three of the four horsemen of the apocalypse in the book in the Bible called the
Revelation to John – and the yellow gunge the cholesterol laden plaque that
clogs up coronary arteries thereby causing heart disease.

Before moving on the relationship between God, evolution,
global warming and heart and population health I fell a need to provide you
with a definition of population health. Here is my definition: [OHP] 'The science and art of preventing disease and
promoting health through the organized efforts of society, organizations, communities,
families and individuals'.

For those of you familiar with definitions of population
health and what it used to be called - public health - you’ll note that this
definition is basically the same as that of Charles-Edward Winslow dating back
to the 1920s[i]
and also that of the Faculty of Public Health – the standard setting body for
specialists in population health in the United Kingdom - although with some
modifications of my own.

An important thing to note about this definition is that it regards
population health as both a science and art which suggests that the arts have
just as much to contribute to population health as the sciences. By arts I do mean art, but also literature,
myth and history which I’ll come on to later. The definition also makes it clear that, when it comes to disease, population
health is about prevention rather than cure.
This definition also begs the questions of what we mean by disease and
health. Here the World Health Organization’s definition of health
is, I think, useful. [OHP]t hat is that: ‘Health is a state of complete physical, mental and social
well-being and not merely the absence of disease or infirmity.’

The word to note here is social. From this definition it follows that health
is not just something individuals might aspire to but also groups or
populations i.e. families, organisations – such as this department, communities
and indeed societies and from this it can be argued that: [OHP] The health of a
population is not just the sum of the health states of the individuals within
that population.

Now I know it will sounds odd to some of you to suggest that
groups rather than individuals can be healthy or unhealthy, and even odder to
suggest that the health of a population is not just the sum of the states of
health of the individuals of which it is composed. But for me these ideas are at the heart – forgive
the pun – of population health and distinguishes it from medicine which might
be defined as the ‘science and art of treating and alleviating the disease of
individuals’.

Do we have any evidence to suggest that the health of a
group is not just the sum of the health states of the individuals within that
group? Well I think we do in the work
of various population health scientists and most strikingly in the analyses of
Richard Wilkinson and colleagues. To take just one example: [OHP] Here is a
graph of income inequality against infant mortality in rich countries. Each point represents a country. The countries with the greatest income inequality
such as the US are to the right. The
countries with the least income inequality such as Sweden and Japan are to the
left. It shows that there is a
relationship between income inequality and infant mortality with countries having
the greatest income inequality experiencing the greatest infant mortality.

Now it is important to note that the X and Y variables on
this graph are not the properties of individuals but of societies. Income inequality can only be measured when
you have two people at least, in relationship with one another. Income inequality can be experienced by an
individual but only when another individual is present. Similarly, but perhaps less obviously, the
infant mortality rate of a county can only be measured when there is a group of
individuals in which more than one child dies and the same may be said of any
disease rate.

I think the properties of groups and their relationship to
health is an important area for future research. Of course societies are clearly not merely
defined by how unequal they are. But
this area of research has been hampered by the notion that there is no such
thing as society – as articulated by Margaret Thatcher in a famous interview
given to Women’s Own in 1987. [OHP]

She said in this interview: "They are casting their
problems at society. And, you know, there's no such thing as society.. There
are individual men and women and there are families. And no government can do
anything except through people, and people must look after themselves first. It
is our duty to look after ourselves and then, also, to look after our
neighbours."

Of course population health does not merely aim to describe
the healthiness or otherwise of individuals and populations but to do something
about what is observed. In addition it is worth emphasising [OHP] that
population health aims to improve the health of groups: societies, communities,
organisations, families and not just individuals. Public health is therefore concerned with
both problems and solutions.
Incidentally some of us think that population health research spends
much too much time on the problems and not enough on the solutions but I do not
have time to go into that issue today.

Turning again to my definition of population health. Another important couple of words in this
definition are ‘organised efforts’.
What are organised efforts? At this point I can’t resist the temptation to show you my
favourite diagramme of the complexity with which population health must
deal. [OHP] This is a map of the causes and
possible solutions of just one population health problem: obesity. It was produced by the UK Government’s
Foresight Programme for the Government Office for Science in 2007. I say favourite but actually I think it obfuscates
rather than enlightens. To me the solution
to the problem of obesity is simple as many of you will know. My solution is to tax sugary drinks. Although I acknowledge that this isn’t going
to be the only measure necessary.

There is no mention of sugary drinks in this map let alone
sugary drinks taxes. The closest you get
to that is ‘the market price of food offerings’ circled here. Rather strangely you get a whole section of
the map devoted to ‘self-esteem’ and ‘psychological ambivalence’ shown here. There is even a box for ‘genetic and
epigenetic predisposition’ shown here. But
how, I ask, does knowing that there is a genetic predisposition to obesity –
which there probably is - help generate a solution?

A better way of explaining the organised efforts necessary
to prevent obesity and indeed the organised efforts necessary to prevent
disease and promote health as a whole is a poem called ‘The Fence or the
Ambulance?’ by Joseph Malins written in 1895.
I’ll read it to you.

Twas a dangerous cliff, as they freely
confessed,

Though to walk near its crest was so
pleasant;

But over its terrible edge there had
slipped

A duke and full many a peasant.

So the people said something would have
to be done,

But their projects did not at all tally;

Some said, "Put a fence 'round the
edge of the cliff,"

Some, "An ambulance down in the
valley."

But the cry for the ambulance carried
the day,

For it spread through the neighboring
city;

A fence may be useful or not, it is
true,

But each heart became full of pity

For those who slipped over the dangerous
cliff;

And the dwellers in highway and alley

Gave pounds and gave pence, not to put
up a fence,

But an ambulance down in the valley.

"For the cliff is all right, if
you're careful," they said,

"And, if folks even slip and are
dropping,

It isn't the slipping that hurts them so
much

As the shock down below when they're
stopping."

So day after day, as these mishaps
occurred,

Quick forth would those rescuers sally

To pick up the victims who fell off the
cliff,

With their ambulance down in the valley.

Then an old sage remarked: "It's a
marvel to me

That people give far more attention

To repairing results than to stopping
the cause,

When they'd much better aim at
prevention.

Let us stop at its source all this
mischief," cried he,

"Come, neighbors and friends, let
us rally;

If the cliff we will fence, we might
almost dispense

With the ambulance down in the valley."

"Oh he's a fanatic," the
others rejoined,

"Dispense with the ambulance?
Never!

He'd dispense with all charities, too,
if he could;

No! No! We'll support them forever.

Aren't we picking up folks just as fast
as they fall?

And shall this man dictate to us? Shall
he?

Why should people of sense stop to put
up a fence,

While the ambulance works in the
valley?"

But the sensible few, who are practical
too,

Will not bear with such nonsense much
longer;

They believe that prevention is better
than cure,

And their party will soon be the
stronger.

Encourage them then, with your purse,
voice, and pen,

And while other philanthropists dally,

They will scorn all pretense, and put up
a stout fence

On the cliff that hangs over the valley.

Better guide well the young than reclaim
them when old,

For the voice of true wisdom is calling.

"To rescue the fallen is good, but
'tis best

To prevent other people from
falling."

Better close up the source of temptation
and crime

Than deliver from dungeon or galley;

Better put a strong fence 'round the top
of the cliff

Than an ambulance down in the valley.

But to return to my title: what have God, evolution, global
warming and heart disease got to do with population health? I’ll take each in turn.

The easiest of these topics to deal with is heart disease
because it is self-evidently a population health problem. And I am going to take it as read that it can
be prevented by improving our diets, increasing our levels of physical
activity, smoking less and reducing our consumption of alcohol.

As I said heart disease is an issue that I have been
concerned with since 1986 when I joined the staff of the Coronary Prevention Group.
In that year coronary heart disease was
responsible for about 180,000 deaths a year in the UK and we could confidently
say that coronary heart disease was the UK’s Number 1 killer. In 2012 coronary heart disease was
responsible for 74,000 deaths and now even the British Heart Foundation
concedes that cancer is the UK’s Number 1 killer with nearly 166,000 deaths a
year.

Can we explain this success story? Here are some slides from a paper I
contributed to. It was published in the
British Medical Journal in 2012 and the first author was one of my DPhil
students – Kate Smolina. The first slide
[OHP] shows this decline in deaths from heart attack – the most acute form of
coronary heart disease - between 1999 and 2007.
The blue line shows the decline in deaths from heart disease overall,
the green line shows deaths from heart disease in hospital and the red line
deaths out of hospital. So the decline
in overall deaths has had nothing to do with improving hospital care. Your chance of dying from a heart attack if
you reach hospital hardly changed over that time.

So what was happening which led to this rapid decline in
people dying from heart disease out of hospital. This slide [OHP] shows that it was two
things: the number of actual heart attacks was falling – the event rate as
described in this slide - and people were living longer after their heart
attacks: case-fatality, as it’s called here, was improving. So why was event rate declining and case
fatality improving? I still think this
question lacks an entirely satisfactory explanation. My friend Simon Capewell has tackled it but
I don’t think he, or anyone else, as yet has given us the full answer.

What we can say is that it wasn't just down to the increasing use of
statins and other drugs that reduce your risk of a heart attack. Here is a slide I have borrowed from Richard
Peto [OHP]. It shows the decline in vascular
mortally as a whole: i.e. deaths from both heart attacks and strokes for the past
50 years. And here is the date of the
publication of the first major study showing the effectiveness of statins as a
drug that reduces your level of blood cholesterol and thereby your risk of
vascular disease [OHP]. You can see
that this trial was published long after the decline in vascular mortality began.

Oh here [OHP] is the Daily Mail’s explanation of our results
published in the British Medical Journal.
For once I think they got it about right but we didn’t actually say this
in our paper. Their headline was – for
those who can’t read it – ‘Heart attack deaths halve in eight years due to
fewer smokers, better diet and improvements to care.

We have come a long way – in past 30 years - in our
understanding of the causes of and remedies for heart disease as illustrated by
this bill-board advert from 1994 [OHP] – when I’d just left the Coronary
Prevention Group – to start what has become the British Heart Foundation Centre
for Non-Communicable Disease Prevention.
The advertising campaign used statistics from a compendium of statistics
on heart disease which the Centre had produced for the BHF. We have continued to produce such a compendium
since 1993, but it is inconceivable that the BHF would use the slogan ‘Cross
your heart and hope not to die’ nowadays

How we explain things brings me to the next issue in my
title: God or rather theology. But
firstly I want to say something about other ologies besides theology and their
contribution to population health.

I think we often suffer from a limited understanding of what
counts as an explanation. Scientific
explanations are not the only sort of explanations we need to help us live our
lives. A framework for thinking about different types of explanations is
provided by the philosopher Ken Wilber in his book ‘A theory of everything’
[OHP]. Wilber divides theories into
four types: individual objective, group/objective, group/subjective and
individual/subjective. An easier way
of understanding this classification of theories is to show how different
disciplines or ‘ologies’ can be classified by this framework [OHP].

So physiological theories are archetypical
individual/objective theories – aiming objectively to study individual
bodies. Modern day psychological
theories are generally of the individual/objective type though in the past they
were more subjective [OHP]. Epidemiology
is the discipline that is most associated with population health. It too seeks objectively to study
individuals – in particular their health status – but as I have suggested
earlier – sometimes seeks objectively to study the health of groups – and
indeed in my opinion it should do more of that. In this it touches upon group/objective
theories such as those generated by sociology [OHP]. Sociology is a discipline that seeks to explain
– largely objectively (at least almost everywhere except France) the
characteristics of groups and in particular societies.

So In the two right hand quadrants we find disciplines that
primarily rely on objective knowledge and on empirical data, preferably
quantified and ideally from experiments.
In the two left hand quadrants we have disciplines that rely primarily
on subjective understanding and on story rather than numbers.

Theology - top left – within which I would include atheistic
theologies (if that isn’t a contradiction in terms) as well as theistic theologies
– generates the archetypical individual/subjective type of theory. But there are also theories which can be
described as group/subjective theories: such as historical theories – bottom
left. Theology is generally thought of
as seeking to explain the individual’s subjective experience of their place in
nature, his/her relationships with others including God, etc. but it, like
epidemiology should, in my view, be more concerned with the collective
experience.

Of course this classification of ologies is hugely
simplistic and many of you will object to where I have put your favourite disciplines.

So how does all this relate to the problem of heart disease? Well firstly different types of theories to
explain the problem, in actual fact, seek to address superficially similar but
actually very different questions [OHP].
For example in relationship to heart disease, individual objective
theories might address the question: Why does he/she have heart disease? Group objective theories: Why do they (as a
group) have heart disease? Group
subjective theories: Why do we (as a group) have heart disease? And individual subjective theories: Why do I
have heart disease?

[OHP] Physiology tells us how heart disease is a result of cholesterol
laden plaque building up in arteries sometimes breaking away to form a clot that
blocks a coronary artery bringing oxygen to the heart. [OHP] Epidemiology gives us some answers to
the question of why heart disease is more prevalent in certain groups rather
than others (incidentally these are some results – published only the other day
– but similar to those I showed you earlier about income inequality and infant
mortality). OHP] History explains how we as a society – such as that of the UK - have
become defined by our patterns of consumption – many of which turn out to be
bad for us – for example our tendency to over consume high sugar foods, leading
to overweight and obesity and in turn to heart disease. [OHP] Theology seeks to explain why human
beings suffer: suffer from diseases such as heart disease. In Christian theology the reasons for
suffering are addressed in the book of Job and in the sayings and stories of
Jesus – both his parables and the narrative of his life.

Different ologies bring different answers to the problem of heart disease
but also propose different solutions. [OHP]
Physiology suggests tackling the build up of cholesterol in arterial plaque through
dietary change or pharmacological treatment.
[OHP] Epidemiology suggests that policies which affect income
distribution may have the additional benefit of reducing overall rates of heart
disease. This is a picture of students
celebrating the fact that the University of Oxford has signed up to being a
Living Wage employer. [OHP] History suggests
that we need to tackle the over-consumption of particular consumer goods such
as sugary drinks through for example increasing their price. This is a billboard urging people in Berkeley,
California to vote for a sugary drinks tax there, which in fact they did. [OHP]
Theology tells us of the importance of eating together and if we do we will
lead happier healthier lives (to cut a rather long story short).

Now these ologies are complementary not competitive in both their
analysis of problems and generation of solutions. This is one reason why the Nuffield
Department of Population Health, at the University of Oxford needs more than
just epidemiologists, but also psychologists and sociologists (as being researchers
in neighboring ologies in my conceptual framework) and dare I say it
theologians.

So that was God – or at least theology – what about
evolution and global warming? I don’t
have time to give them much attention but I will briefly say something about
them.

Firstly evolution or rather evolutionary biology. I mentioned earlier that particular theory of
evolution that was summarised in Richard Dawkin’s book, ‘The Selfish Gene’, published
in 1975. This theory called Neo-Darwinism
and its fore-runner Darwinism has, I think, had a profound effect on our
thinking in all disciplines not just biology.
The influence of Darwinism on other disciplines including psychology,
sociology, economics and of course theology is brilliantly laid out in this
book [OHP] entitled Darwin’s Metaphor, by Robert Young, and published in 1985,
from which I have taken just one quote, but I could have taken many.

A particular effect of Neo Darwinism on our ideas, and relevant
to my personal perspective on population health, is its influence upon our
ideas about the nature of societies and whether they might be described as
healthy, irrespective, at least to some degree, of the health of the individuals
of which they are composed.

You’ll remember that Margaret Thatcher said that: ‘There is
no such thing as society’. In, to my
mind, an extraordinary interview with Eddie Mayer on Radio 4’s iPM Programme in
April 2013, Ian Swingland, now Emeritus Professor in Conservation Biology at
the University of Kent says: “Thatcher eschewed the idea of society because of
a high table dinner at Magdalen College at Oxford [in March 1978. [At this dinner] ‘Richard Dawkins convinced
her there was no such thing as society just individual.” Swingland himself had attended this
dinner. Here is a transcript of that
interview which you can read at your leisure. I am looking forward to the second volume of Richard
Dawkin’s autobiography to see whether Dawkin’s confirms Swingland’s view.

And secondly global warming. Now anthropogenic global warming is a
problem which is similar to heart disease.
It, like heart disease, threatens our physical, mental and societal well-being. To be concerned about human health and not
about the health of the planet seems increasingly absurd, given that, if the
predictions of those who are tracking climate change are correct, human health
will, in the future, be profoundly affected by global warming.

Anthropogenic global warming, like heart disease, can be
explained in various ways and will require different types of solution. But explanations
for and solutions to global warming seem extraordinarily similar to those for
heart disease: we would reduce our risk of heart disease and save on fossil
fuels if ate more plant based foods and less meat and walked and cycled more
rather than travelling by car. Moreover, like population health problems,
global warming will only be solved through the organized efforts of society,
organizations, communities, families and individuals.

So finally I would like to close with some words of a hymn
which I we sung in my church yesterday.
They seems peculiarly apt to what I have been saying.

Spirit of
truth arise

Inspire the
prophet’s voice

Expose to
scorn the tyrant’s lies

And bid the
poor rejoice

O Spirit,
clear our sight,

All
prejudice remove,

And help us
to discern the right,

And covet
only love.

Give us the
tongues to speak

The words of
love and grace

To rich and
poor, to strong and weak

In every
time and place

Enable us to
hear

The words
that others bring

Interpreting
with open ear

The special
song they sing

I know I said I would only give two acknowledgements in this
lecture but I have a few more. Thank you
all for coming and thank you for listening.
And thank you too to Charlotte Payne for providing some sushi made with
edible insects to eat as snacks after this lecture. I’ll leave you to work out the connections
between insect sushi and God, evolution, global warming, heart disease and
indeed population health.